racks don't require a do_after to setup, unlike other structures.

## Testmerges
#11589: 'byondoidc' by hry-gh at commit 80574d4a6d
#11660: 'achievement integration' by hry-gh at commit cb1b1a3b36
#11677: 'Xenomorph on dropship alert now only occurs after landing' by carlarctg at commit 5d4d3c1257
#11636: 'Fix: Cades stacking on top of each other.' by MistChristmas at commit 03c79f5178
#11615: 'Xeno Fire Immunity Refactor x2 + Hive Fire Resistance Buff' by Drulikar at commit e425813335
#9774: 'Adds a minesweeper game to a bunch of interactions.' by kiVts at commit bd1bb5d5be
#10999: 'Fix of various plane related issues' by Blundir at commit f85a7153c4

## Round ID
32373

## Description of the bug
The folding shelf items, which can be carried in a backpack or other large item slot container can be instantly deployed, afterwards a bipod can be deployed on it with no setup channel.

## What's the difference with what should have happened?
Proposed solution would be to make the folding shelves have a setup channel like the folding cades, tables, and other equivalent places where bipod can be deployed.

## How do we reproduce this bug?
Get a folding shelf, press z to deploy.
move back one square and then setup a bipod on it.

## Attached logs
```
N/A
```

## Additional details
- Author: Wriath
- Admin: the mistchristmas
- Note: None